Research and analysis of the hottest virtual reali

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Research and analysis of virtual reality technology

Abstract: This paper mainly discusses the concept, components and principle of virtual reality technology; This paper focuses on the method and significance of virtual design, and expounds the related technologies of virtual manufacturing

key words: virtual reality virtual design

1 virtual reality technology

what we call virtual reality is the simulation of thinking space-time in the real world, that is, in addition to space-time, it also includes immersive man-machine exchange interface. This immersive and interactive feature is that designers can better observe and process three-dimensional design elements in the virtual space, understand the composition of various components, the coordination of assembly, etc, And make better judgment and selection to achieve the optimal design

virtual reality, also known as VR, has three basic characteristics: autonomy, interaction, and immersion. It is a computer system that can create and experience virtual world. It uses computer technology to generate a realistic three-dimensional world, so that users can start from their own point of view, use natural skills and some devices to interact and observe the generated virtual world objects. This computer-generated interactive simulation environment is characterized by realistic feeling, natural interaction, and rapid response to human viewpoints and behaviors

the equipment of virtual reality system is mainly composed of the following parts:

host computer, which is used to generate virtual scenes; Surround stereoscopic display screen as visual equipment (such as helmet); Data glove as an interactive input device; Distributed stereo as auditory equipment; And corresponding computer software

"virtual reality" technology was first applied to aircraft flight training, which requires the system to make corresponding simulation response with the different reactions of the trained pilots. Due to the sharp decline of computer hardware cost, the improvement of computing speed and the rapid development of software technology, the application of virtual reality technology has been widely developed

1.1 several key devices in virtual reality

(1) desk mounted systems

these systems use computers to process the scenes of the required left and right eye channels and project them onto ordinary displays, and then display the left and right eye images separately through specially designed glasses. It can provide a higher resolution, and allow other users to have a synchronous experience by increasing the number of glasses. It costs less, but it has certain requirements for the observation position and angle. The tools used to construct such systems are VRML (virtual reality

modeling language) and quicktimevr. These two tools can publish the product modeling of the virtual world on the Internet

(2) head mounted system

this kind of system completely immerses the user's personal viewpoint in the virtual environment. The system includes two micro displays supported by the helmet, which are configured in front of the eyes, and sometimes it is necessary to configure data gloves. This system can provide omni-directional vision, strong realism, and is convenient for the design of complex components

(3) perception glove is also called cyber grasp

it was originally developed by the U.S. Navy for remote-control robots. Now it is gradually applied in the automotive field. There are various wires and sensors on this kind of gloves. Through the operator's hand to do various precise and small traction actions, various parts generated by the computer are perceived as real. The instructions of the computer are transmitted to a controller that can be placed on the desktop or worn on the belt. The cable on the controller gives pressure and traction, so that people wearing sensing gloves can "feel" the imaginary objects of the computer. At the same time, a hand is repeating the action of the operator's hand on the computer screen. This kind of gloves is made by using the principle of force feedback. Its other product is (cyber glove), which can only display the position without the function of force feedback. These two products play an important role in automobile manufacturing. It can be used in the training of workers before production, and engineers can use it to design the assembly line, because it can determine whether various parts can be assembled correctly and easily before the production line is completed. Sensing gloves can also be used as information feedback for experts, because it can show various skills adopted by skilled workers. It can also be used to train novices and verify product design problems, as well as a series of problems such as how to easily install various oil pipes on or off the vehicle

2 enhanced display of virtual reality

in order to integrate the idea of augmented reality into the virtual reality system, solve the problems of virtual reality and virtual objects, properly grasp the changes of virtual reality and highlight the key points, so as to efficiently complete the work that cannot be completed in the real world. With the rapid development of IT industry, the mature application of database, multimedia, network, artificial intelligence, computer graphics processing and other software technologies, as well as the development of corresponding hardware technology, provide a reliable guarantee for the augmented reality technology of virtual reality

2.1 virtual reality combination technology

in the process of virtual manufacturing of products, the virtual environment where the products are located is often very complex. In order to reduce the workload of modeling, the main work of modeling is focused on the manufacturing of virtual products. First, we take photos or videos of the environment where the products are located, and convert the photos or videos into special scenes through the research on the algorithm of converting two-dimensional graphics to three-dimensional graphics. This greatly reduces the workload of virtual manufacturing, and thus focuses on the manufacturing of virtual products

2.2 collision detection technology

collision detection is one of the indispensable technologies in virtual design and manufacturing. Database technology is an effective way to solve collision detection, that is, to establish model database in the process of modeling. When the model is in the process of virtual assembly, an appropriate small time slice is given. At the end of each time slice, the system checks the positional relationship between all objects in the scene. If the space occupied by objects overlaps, it is considered that there is a collision. In the process of virtual assembly, the augmented virtual reality system should be able to report and propose modification suggestions for unreasonable structural parameters. At present, the development of artificial intelligence technology is relatively mature. Combine artificial intelligence technology with database technology to establish an intelligent database of virtual scenes, which should have the functions of data query, data mining, relational data verification and so on. The relatively perfect augmented virtual reality system can render in real time, perform assembly, interference and collision detection, observe the scene in the way of virtual browsing, and truly express the product to be designed through color, transparency, material, texture, lighting, etc. this augmented virtual reality system has the functions of intelligence, visualization, integration and networking, and provides a free imagination space for product design

3 design of virtual environment

virtual design is a new interdisciplinary technology. It involves many disciplines and professional technology. Based on virtual reality technology and taking the design product as the object, designers are liberated from the traditional keyboard and mouse, so that they can interact with the multidimensional information environment through many sensors, and virtual design technology can greatly reduce the manufacturing of physical models and prototypes

One of the origins of the virtual design method is that the current CAD software technology is far from being able to adapt to the current rich and colorful product design tasks. The current CAD software is far from the requirements of theoretical design. It can only be said to be a "two-dimensional electronic drawing board". The current CAD software system can only help designers build models and analyze and evaluate design schemes according to the fixed mode of the system, but it does not have flexible and creative functions. However, the design function of multidimensional space is relatively weak

3.1 the main shortcomings of the current CAD software system

1) the data and instruction input methods of keyboard and two-dimensional mouse are unnatural, lack of interactive function, and designers cannot feel the design product from touch and hearing

2) the software operation is complex and difficult to master, especially for people who are not familiar with computers. Professional technicians must spend a lot of energy to learn the application of software, and the cumbersome operation seriously affects the creative thinking of designers

3) the current software 3D modeling system is difficult to realize when the design of the concept car does not need specific dimensions

4) the current CAD software system still needs a certain physical model and prototype to verify the working performance of products and improve the cost of products

however, virtual design method is essentially different from traditional CAD technology. When applied, virtual design can give play to the design idea of multi-dimensional space, and can be designed by considering force, deformation analysis, assembly, etc. or integrating with other software. Therefore, its computer-aided design/manufacturing/assembly function is greatly enhanced. In addition, virtual design can also use network technology, multimedia, telecommunication, engineering database, spirit mirror technology to realize distributed parallel design

3.2 main technologies involved in virtual design

1) virtual modeling

2) engineering and data analysis

3) concurrent design of networks

4) visualization during parameter interaction

3.3 the key scientific theoretical basis of virtual design

1) the modeling theory and method of holographic products

2) planning, integration and functionalization of the design process

3) ergonomics in virtual environment

4) tool library and database for generating virtual environment

5) integration of virtual environment and design process

3.4 virtual design can be divided into two categories according to the level of configuration

one is a cheap design system based on PC; The other is high-end product development and design system based on workstation. Although it is divided into two categories, the working principle is the same. PC based design system, mainly because of its low cost, is very suitable for the development of small virtual design system, and its users are relatively wide, so it has a broad market prospect. With the rapid improvement of PC performance, more and more problems can be solved by PC. for example, UG, CAXA, PROE, etc., which are widely used at present, are all microcomputer versions. CATIA, one of the software used in workstations, has also issued microcomputer versions. However, the current PC development is still not perfect, and it is difficult to be competent for the virtual design of large and complex products, so powerful high-end workstations are used to carry out the virtual design of large and complex products

3.5 virtual design system is classified according to the application situation

virtual design is a new design system based on computer aided design (CAD) and using virtual reality technology. This design system can be divided into enhanced visualization system and virtual reality based CAD system

(1) the enhanced visualization system

uses the current CAD system for modeling, and the virtual environment system converts the data format appropriately, and then outputs the virtual environment. In the virtual environment, using three-dimensional interactive devices (such as helmet mounted display, data gloves, etc.), designers can observe the virtual model from multiple perspectives in a "virtual" real environment. Virtual devices currently in use

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